These Hard Line 1-Layer 110mm wheels are the NEXT step in personalizing YOUR scooter according YOUR riding! 3 different hardness all above the "Standard" Hardness!: SNOWBALLS - just ABOVE the "Standard" hardness; PANTHERS -: just above the Snowballs Hardness; SEWERCAPS -: the HARDEST scooter wheels out there! The Urethane is Hand Poured in Holland according to our own, Proprietary formulas. Cores are made from Certified, 6061 aluminum extrusion and machined to shape.